721057 has 2 divisors, whose sum is σ = 721058. Its totient is φ = 721056.

The previous prime is 721051. The next prime is 721079. The reversal of 721057 is 750127.

It is an a-pointer prime, because the next prime (721079) can be obtained adding 721057 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 720801 + 256 = 849^2 + 16^2 .

It is a cyclic number.

It is not a de Polignac number, because 721057 - 2¹¹ = 719009 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360528 + 360529.

It is an arithmetic number, because the mean of its divisors is an integer number (360529).

2⁷²¹⁰⁵⁷ is an apocalyptic number.

It is an amenable number.

721057 is a deficient number, since it is larger than the sum of its proper divisors (1).

721057 is an equidigital number, since it uses as much as digits as its factorization.

721057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 490, while the sum is 22.

The square root of 721057 is about 849.1507522225. The cubic root of 721057 is about 89.6719331601.

The spelling of 721057 in words is "seven hundred twenty-one thousand, fifty-seven".